Chapter 17 “Critical Reasoning”
·
Based on the logical construction of arguments
·
Can appear anywhere in the verbal section
·
~ ¼ of the verbal section, ~10 questions
·
Usually a short passage (20-100 words) with a
single question and 5 multiple choice answers
·
Not categorizable by subject, often hypothetical
scenarios
·
Read carefully, attend to language use,
interpret literally, be very precise
·
8 question types
·
Use PoE
https://www.youtube.com/watch?v=xpAvcGcEc0k
– Monty Python’s Flying Circus “Argument Clinic” sketch
Arguments are not:
-
Abuse
-
Assault
-
Complaints
-
Mere contradiction
Arguments are: a collective series of statements intended to
establish a definite proposition.
Arguments have three parts:
1.
Conclusion – what the author tries to persuade
the reader to accept; key words include: therefore, thus, hence, so,
consequently, in conclusion, accordingly, as a result, wherefore, we may infer,
we may conclude, it follows that, it must be that, entails that, for this
reason, implies that; key words for opinions include: suggest, believe, hope,
indicate, argue
2.
Premise(s) – evidence supporting the conclusion;
key words include: because, given that, result of, since, due to, based on,
for, inasmuch as, as shown by, for the reason that, as indicated by, in that,
may be inferred from, as, seeing that, owing to
3.
Assumptions – unstated in the passage, but required
to connect premise(s) to conclusion, never explicit, but implied
Gaps – gaps in reasoning show up as gaps in language, so
look for words/phrases/ideas that appear in ONLY the conclusion but NOT in the
premises. Identify shifts in wording to find these logical gaps.
Other information in the passage may include: extraneous
ideas, background information, opposing points of view, etc. These are NOT part
of the argument.
Two categories of arguments are deductive and inductive.
Most arguments in standardized tests are inductive arguments, based on the
accumulation of evidence. Deductive arguments, by contrast, are usually based
on definitions and/or categories.
For example, one deductive argument:
All humans are mortal.
Socrates is human.
Therefore, Socrates is mortal.
By contrast, one inductive argument:
The sun rose yesterday, and the day before that.
The sun has risen every day of recorded history.
Therefore, the sun will rise tomorrow.
(The hidden assumption: the future will be like the past)
Common Reasoning Patterns:
·
Causal – connect two events as cause and effect
o
Two assumptions:
§
There is no other cause
§
These are not coincidental
o
HOWEVER correlation does NOT equal causation –
so be very careful
·
Planning – plans designed to solve problems
o
Assumption: There is no problem with the plan
o
HOWEVER most plans DO have problems, so try to
look for possible obstacles
·
Sampling – evidence about a sample, smaller
group proves the same claim is true about the larger population
o
Assumption: the sample group represents the
larger group accurately
o
HOWEVER most samples fail to be wholly
representative, so look for ways the larger group might differ from the sample
group
·
Interpretation of evidence – sometimes
statistical; an interpretation where the premise becomes the conclusion
o
Assumption: there is no other way to interpret
the evidence
o
HOWEVER more often there ARE other ways to
interpret the evidence
·
Analogy – similarities between two things in one
respect mean that there are further similarities between those two tings
o
Assumption: One thing is similar to the other in
all or most ways
o
HOWEVER there are often far more differences
than similarities, so look for those important disanalogies or dissimilarities
Question Types: assumption, weaken, strengthen, inference,
resolve/explain, evaluate, identify the reasoning, flaw
Basic approach:
1.
Identify the question – look for words or
phrases in the question stem to identify the type, which will tell you what
approach is best. Types of questions include:
a.
Assumption (p. 307) – identify the unstated
claim; key words: presupposition, expectation, assumption
b.
Weaken (p. 307) – undermine the way the
conclusion comes from the premise(s); key words: weaken, undermine, cast doubt)
c.
Strengthen (p. 307) – add more support to an assumption;
key words: strengthen, support, justify
d.
Inference (p. 308) – identify an additional
conclusion; key words: inference, support, strengthen
e.
Resolve/Explain (p. 308) – identify what
supports the two different ideas; key words: resolve, explain, paradox, discrepancy,
apparent contradiction
f.
Evaluate (p. 309) – test the assumption(s); key
words: evaluate, assess, experiment, determine, test
g.
Identify the reasoning (p. 309) – identify the
technique or method the author uses; key words: technique, strategy, method,
roles
h.
Flaw (p. 309) – identify the problem or
vulnerability in the argument; key words: vulnerable, criticism, flaw
i.
Logical fallacies: yourlogicalfallacyis.com
2.
Work the passage – read and take notes
a.
Assumption – identify premises and conclusions,
then look for what bridges the gap
b.
Weaken – attack the assumption
c.
Strengthen – reinforce the assumption
d.
Inference – what must be true given the evidence
e.
Resolve/explain – what can make both claims true
f.
Evaluate – determine what test will mean the
claim is true or false
g.
Identify the reasoning – describe the structure
of the argument
h.
Flaw – what exposes a weakness
3.
Predict the answer – imagine what a good answer
will do
a.
Assumption – will connect premise to conclusion
(NOT new information)
b.
Weaken – will widen the gap or attack the
assumption
c.
Strengthen – will support
premise/assumption/conclusion or introduce new information
d.
Inference – will be supported by the passage
e.
Resolve/explain – will allow both claims to be
true
f.
Evaluate – will make it possible to determine if
a claim is true or false
g.
Identify the reasoning – will mirror the
argument structure
h.
Flaw – will articulate a faulty assumption or
other claim
4.
Use PoE – first, remember that half right = all
wrong
a.
Assumption – try the negation test: negate your
preferred answer and see if it changes the conclusion. Eliminate:
i. Out
of scope
ii. Extreme
language
b.
Weaken – ask how each choice affects the
author’s claim. Eliminate:
i. Out
of scope
ii. Extreme
Language (maybe keep)
iii. Strengthen
the argument
c.
Strengthen – ask how each choice affects the
author’s claim. Eliminate:
i. Out
of scope
ii. Extreme
language (maybe keep)
iii. Weaken
the argument
d.
Inference – ask how close the choice is to what
is in the passage. Eliminate:
i. Additional
assumptions
ii. Out
of scope
iii. Extreme
language
e.
Resolve/explain – ask what choice explains the
conflict and lets both claims be true. Eliminate:
i. Out
of scope
ii. Make
conflict worse
iii. Address
only one side
f.
Evaluate – look for a good test of the truth of
a claim. Eliminate:
i. New
information
ii. Information
that does not connect premises to conclusions
iii. Out
of scope
g.
Identify the reasoning – accurate descriptions
of the argument. Eliminate:
i. No
match to structure
ii. Partial
matches to structure
h.
Flaw – accurate descriptions of problems with
the argument. Eliminate:
i. No
mention of flaws
ii. Out
of scope
iii. No
match to argument
iv. Partial
matches to argument
Examples on p. 314-329
Practice identifying questions p. 330
No comments:
Post a Comment